It has been my experience that in Aikido dojo (without formal randori) practice against resistance does happen. It is after a certain period of time when a practitioner gets to a certain level and develops good relationships with his/her dojo mates. I never resist partners whom I cannot trust and I often do resist those whom I do trust and whom I like. This is the only way, in my opinion, to do freer practice without formally setting up resistance practice. If someone says in a critical way that there is no resistance training in Aikido, I wonder if that person may not have dojo mates that like and trust him.